Red and Green Phantom Quartz Approx. 2.4"; 350g A Phantom is a crystal or mineral deposit within a crystal. While the color of Phantoms will vary from crystal to crystal, depending upon the type of mineral of which they are made, Phantoms look like the “ghost” of a crystal within another crystal. Phantoms are formed when the growth of a crystal has been interrupted and then begins to grow again. Often, the original mineral gets washed away, leaving only the Quartz to grow afterwards.